Sealable container linings and sealable containers

ABSTRACT

A sealable container includes a substantially rigid housing having an inner surface and an opening and a liner including: a) a collar formed at least from a fluoropolymer material and sized and shaped to removably engage the opening in the housing; and b) a flexible bag, having an opening, sealed to the collar, and including a composite of an abrasion resistant reinforcing material and an inner fluoropolymer material that is substantially inert to content in the container and compatible with the fluoropolymer material of the collar, the bag being sized and shaped to pass through the opening in the housing and expand such that the abrasion resistant reinforcing material can be in contact with at least a substantial portion of the inner surface of the housing.

TECHNICAL FIELD

This disclosure relates to sealable container linings and sealablecontainers utilizing sealable container linings.

BACKGROUND

Very pure chemicals such as organic solvents, in particular, must beplaced in containers for transport that satisfy a number of needs. Thecontainers must withstand the potential for damage through ordinarycommercial transportation means, must be liquid tight, and must be inertto the chemicals or solvents within the container. A representative typeof transport container is disclosed in U.S. Pat. No. 4,741,457, forexample. Another type of transport container is the NOWPak® DrumDispense System manufactured by ATMI Packaging.

Very pure chemicals or solvents transported in smaller containers, suchas 10 to 20 liters, typically may be transported from the point offilling to the ultimate customer destination without problems such asleakage, contamination or the like. However, when the size of thecontainer increases to larger quantities, such as 100 liters to 200liters or even more, which is quite desirable from an economic andefficiency standpoint, there is a significant increase in the amount ofleakage and contamination of the container contents.

The problems appear to be that small holes propagate in the containerlining during transport which permits leakage and/or contamination ofthe contents. Also, there tends to be an increased occurrence ofproblems associated with the connection between the flexible liner ofthe container and the liner ring seated in the container opening. Thus,there is a need to provide a container that can safely and effectivelytransport liquid chemicals by ordinary transportation means withoutleakage and without contamination of the container contents.

SUMMARY

Provided herein is a sealable container including a substantially rigidhousing having an inner surface and an opening, and a liner including:a) a collar formed at least from a fluoropolymer material and sized andshaped to removably engage the opening in the housing; and b) a flexiblebag, having an opening, sealed to the collar, and including a compositeof an abrasion resistant reinforcing material and an inner fluoropolymermaterial that is substantially inert to the contents of the containerand compatible with the fluoropolymer material of the collar, the bagbeing sized and shaped to pass through the opening in the housing and toexpand such that an outer surface of the flexible bag can be in contactwith at least a substantial portion of the inner surface of the housing.

Also provided is a sealable container lining including a collar formedat least from a fluoropolymer material and sized and shaped to removablyengage an opening in a liner housing, and a flexible bag, having anopening, sealed to the collar, and including a composite of an abrasionresistant reinforcing material and an inner fluoropolymer material thatis substantially inert to the contents of the container and compatiblewith the fluoropolymer material of the collar, the bag being sized andshaped to pass through the opening in the liner housing and to expandsuch that an outer surface of the flexible bag can be in contact with atleast a substantial portion of an inner surface of the housing.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a schematic cross section of a container suitable fortransporting liquids such as pure chemicals or solvents.

FIG. 2 is a schematic cross section of a portion of the container liner.

FIG. 3 is a schematic cross section of another liner.

FIG. 4 is a schematic cross section of yet another liner.

FIG. 5 is an exploded schematic cross section of a neck portion of acontainer of FIG. 1.

DETAILED DESCRIPTION

It will be appreciated that the following description is intended torefer to specific representative examples of structure selected forillustration in the drawings and is not intended to define or limit thedisclosure, other than in the appended claims.

Without being bound by any particular theory, it is believed that oneproblem with leakage and contamination associated with larger sizecontainers lies with the fact that the containers are typically onlyfilled to about 90% of their ultimate capacity prior to transport totheir ultimate destination. This partial filling allows for temperaturechanges that occur during transportation to permit expansion andcontraction of the material within the liner. Leaving about 10% of thetotal capacity of the liner unfilled permits such expansion withoutdanger of the flexible liner bursting or rupturing due to excessivepressure. However, when the contents of the container are at less thantheir full expansion capacity, such as at 90%, or 92% or 93%, forexample, there is sufficient space for the liquids to move within theliner either gently depending on the handling circumstances, orcomparatively violently.

Given the volume of the liquid and its accompanying mass, the movementwithin the flexible liner can cause the formation of pinholes or evensmall tears in the relatively thin flexible liner, typically having athickness of about 2 to 10 mils. Such movement of liquid within acontainer relative to the liner may occur when the container istransported by forklift, hand truck or even in a moving vehicle. Thismovement causes the liquid to move within or “slosh” around thecontainer, particularly where there is space at the upper portion of theliner and where the neck of the liner is not fully expanded into contactwith the inner surface of the container, thereby causing the upperportion of the liner to intermittently and repeatedly move along theinner surface of the container or fold over onto itself. As a result ofthe movement along the inner surface, the liner develops pinholes fromthe abrasive movement and/or folds onto itself creating sharp creaseswhich itself may cause additional pinholes. Moreover, such movement ofthe liquids can place stress at the connection between the flexibleliner and its collar seated on the opening of the liner housing.

It has been discovered that solutions to this problem include providinga sealable and flexible container lining which includes a collar formedfrom a fluoropolymer material which is sized and shaped to removeablyengage the opening in the container housing; and a flexible liner baghaving an opening that is sealed to the collar. The flexible liner bagcomprises a composite of an abrasion resistant reinforcing material andan inner fluoropolymer material that is substantially inert to thecontents of the container and compatible with the fluoropolymer materialof the collar. The bag is sized and shaped to pass through the openingin the housing and may expand such that an outer surface of the flexiblebag can be in contact with at least a substantial portion of the innersurface of the housing. Using an inner fluoropolymer material as theinterior flexible liner is desirable as it is inert to many chemicalstypically used in larger containers such as a wide variety of organicsolvents.

On the other hand, the abrasion resistant reinforcing material providesabrasion resistance and strength to the exterior portion of the liner toprevent the formation of pinholes and tears typically caused by themovement of liquid within standard liners.

The inner fluoropolymer material may be selected from a wide variety offluoropolymer materials. Representative examples include at least onematerial selected from PFA (perfluoroalkoxy), PTFE(polytetrafluoroethylene), ECTFE (ethylene chlorotrifluoroethylene), FEP(fluorinated ethylene propylene) and ETFE (ethylenetetrafluoroethylene). These are merely representative fluoropolymermaterials and other known fluoropolymer materials may be used asdesired.

The abrasion material reinforcing material can be selected from a widevariety of abrasion resistant materials such as, for example, at leastone selected from fiberglass webs, LDPE, polyamides and the likeprovided in various forms such as, for example, fibers, yarns,particles, aggregates, fabrics and the like. Various types of NYLON®material may be used as preferred polyamides.

The flexible liner collar should also be formed at least from afluoropolymer material. The fluoropolymer material may be the same as ordifferent from that of the inner fluoropolymer material of the flexibleliner bag. Preferred materials include PFA and PTFE, for example.

An unexpected problem has also been discovered when connecting theflexible liner bag having the abrasion resistant material to the linercollar. This connection must be liquid tight and resistant to thestresses applied to that connection point as the liquid moves within theliner. While the abrasion resistant reinforcing material solves thetearing problem by adding strength to liners, introducing the abrasionresistant reinforcing material into the liner, however, can cause a newproblem—the ability to successfully connect the flexible bag to thecollar. This is because the abrasion resistant reinforcing materialtypically has physical characteristics such as softening or meltingtemperatures different from the fluoropolymer material of the collar,thereby making it more difficult to have a reliable seal or connectionpoint between those two components. For example, when the abrasionresistant reinforcing material is a fiberglass web, that web materialhas very different chemical and physical characteristics and would notlikely be as easily sealed to the collar. Despite the incompatibility ofthose materials, it was discovered that it is possible to reliably sealthe composite material of the flexible bag to the collar byconventional, known means such as heat welding, as one example.

Turning now to the drawings, FIG. 1 shows a sealable container 10 whichincludes a substantially rigid housing 12 and a flexible liner 14 sizedand shaped to fit within the housing 12. The housing 12 includes anupper flange 16 which essentially assists in protecting the neck portionof the housing and a lower flange 18 that helps to stabilize the bottomof the container 10. The substantially rigid housing 12 can be made fromany number of high strength materials such as fiberglass materials, hardplastics, various metals such as stainless steel or the like.

FIG. 1 shows the liner 14 in a fully expanded configuration wherein theliner is adjacent essentially to the entirety of the inner surface ofhousing 12. The liner 14 comprises a collar 20 and a flexible bag 22.The flexible bag 22 may be a composite that can be formed in severalconfigurations. A particularly advantageous configuration is a pluralityof layers. Representative, non-limiting examples include theconfigurations shown in FIGS. 2 and 3, for example. In that regard, FIG.2 shows a two layer configuration wherein an inner fluoropolymermaterial is shown as layer 24 and the abrasion resistant reinforcingmaterial is shown as layer 26. These are distinct layers laminatedtogether by any known means. FIG. 3 shows the same distinct layers 24and 26. However, a distinct adhesive layer 28 is sandwiched betweenlayers 24 and 26.

FIG. 4 shows a composite wherein the layers are not distinct in the samemanner as in FIGS. 2 and 3. The inner fluoropolymer material and theabrasion resistant reinforcing material are combined into a single layer30 which, in this instance, has an upper portion 32 that is primarilyformed of the inner fluoropolymer material and a lower portion 34 thatis primarily the abrasion resistant reinforcing material. This structuremay be made by known methods such as, for example, by casting thefluoropolymer material over the abrasion resistant material orimpregnating the fluoropolymer material into the abrasion material.Other configurations with additional and/or different distinct ornon-distinct layers or combinations thereof are contemplated.

The flexible bag 22 is typically a thin bag having a wall thickness ofabout 0.002 inches (0.0508 mm) to about 0.010 inches (0.254 mm) althoughother thicknesses may be used. A wall thickness of about 0.004 inches(0.1016 mm) is preferred. The wall thickness of the overall bag can beinfluenced by the number of layers as shown in FIGS. 2-4. Also, thethicknesses of the various layers can be varied with respect to oneanother. The configuration shown in FIG. 4 is typically the thinnest ofthe layers or configurations of the flexible bag since the fluoropolymermaterial in that instance may be cast over at least one side of theabrasion resistant material, which provides maximum functionality withminimum thickness.

FIG. 5 shows an exploded view of a neck portion 36 of housing 12 andliner 14. Flexible liner 14 includes not only flexible bag 22, but alsocollar 38. Collar 38 may, for example, be heat welded to the innerfluoropolymer material of flexible bag 22. The collar 38 is seated onopening 40 of neck portion 36. The neck portion 36 has a plurality ofthreads 42 which engage threads 44 of cap 48.

This arrangement allows for the flexible liner 14 to be inserted throughopening 40 and have collar 38 seated in a fixed position at opening 40so that it will not move during transportation. It also serves as apoint to anchor the flexible liner 14 for potential expansion intosubstantially complete contact with the inner surface of housing 12. Cap48 sealingly engages the flange portion 46 of collar 38 and compressesflange portion 46 between cap 48 and opening 40. This creates a reliableseal during transportation.

Thus, the user procures an empty housing 12, inserts flexible liner 14through opening 40, fills flexible liner 14 to a preferred capacity suchas about 90%, and then seals the container for transport. This system isable to reliably transport containers full of liquids such as purechemicals, organic solvents or the like in large quantities such as 100to 200 liters or more without developing pinholes in the flexible bag 22or tears between the collar 38 and flexible bag 22.

Although apparatus and methods have been described in connection withspecific forms thereof, it will be appreciated that a wide variety ofequivalents may be substituted for the specified elements describedherein without departing from the spirit and scope of this disclosure asdescribed in the appended claims.

1. A sealable container comprising: a substantially rigid housing havingan inner surface and an opening; and a liner comprising: a) a collarformed at least from a fluoropolymer material and sized and shaped toremovably engage the opening in the housing; and b) a flexible bag,having an opening, sealed to the collar, and comprising a composite ofan abrasion resistant reinforcing material and an inner fluoropolymermaterial that is substantially inert to contents of the container andcompatible with the fluoropolymer material of the collar, the bag beingsized and shaped to pass through the opening in the housing and expandsuch that an outer surface of the bag can be in contact with at least asubstantial portion of the inner surface of the housing.
 2. The sealablecontainer of claim 1, wherein the inner fluoropolymer material is formedfrom at least one material selected from the group consisting of PFA(perfluoroalkoxy), PTFE (polytetrafluoroethylene), ECTFE (ethylenechlorotrifluoroethylene), FEP (fluorinated ethylene propylene) and ETFE(ethylene tetrafluoroethylene).
 3. The sealable container of claim 1,wherein the collar and the inner fluoropolymer material are heat weldedtogether.
 4. The sealable container of claim 1, wherein the abrasionresistant reinforcing material is at least one selected from the groupconsisting of a fiberglass web, an LDPE layer and a polyamide layer. 5.The sealable container of claim 1, further comprising an adhesive layerpositioned between the abrasion resistant reinforcing material and theinner fluoropolymer material.
 6. The sealable container of claim 1,wherein the bag has a thickness of about 0.002 inches (0.0508 mm) toabout 0.010 inches (0.254 mm)
 7. The sealable container of claim 1,wherein the inner fluoropolymer material is cast over at least one sideof the abrasion resistant reinforcing material.
 8. A sealable containerlining comprising: a collar formed at least from a fluoropolymermaterial and sized and shaped to removably engage an opening in a linerhousing; and a flexible bag, having an opening, sealed to the collar,and comprising a composite of an abrasion resistant reinforcing materialand an inner fluoropolymer material that is substantially inert tocontents of the lining and compatible with the fluoropolymer material ofthe collar, the bag being sized and shaped to pass through the openingin the housing and to expand such that an outer surface of the bag canbe in contact with at least a substantial portion of an inner surface ofthe housing.
 9. The liner of claim 8, wherein the inner fluoropolymermaterial is formed from at least one material selected from the groupconsisting of PFA (perfluoroalkoxy), PTFE (polytetrafluoroethylene),ECTFE (ethylene chlorotrifluoroethylene), FEP (fluorinated ethylenepropylene) and ETFE (ethylene tetrafluoroethylene).
 10. The liner ofclaim 8, wherein the collar and the inner fluoropolymer material areheat welded together.
 11. The liner of claim 8, wherein the abrasionresistant reinforcing material is at least one selected from the groupconsisting of a fiberglass web, an LDPE layer and a polyamide layer. 12.The liner of claim 1, wherein the bag has a thickness of about 0.002inches (0.0508 mm) to about 0.010 inches (0.254 mm)
 13. The liner ofclaim 8, wherein the inner fluoropolymer material is cast over at leastone side of the abrasion resistant reinforcing material.
 14. A sealablecontainer for solvents comprising: a substantially rigid housing havingan inner surface and an opening; and a liner comprising: a collar formedat least from a fluoropolymer material which is at least one selectedfrom the group consisting of PFA and PTFE and sized and shaped toremovably engage the opening in the housing; and a flexible bag, havinga thickness of about 0.002 inches (0.0508 mm) to about 0.010 inches(0.254 mm) and an opening, heat sealed to the collar, and comprising acomposite of an abrasion resistant reinforcing material which is atleast one selected from the group consisting of a fiberglass web, anLDPE layer and a polyamide layer, and an inner fluoropolymer materialthat is substantially inert to contents of the liner, compatible withthe fluoropolymer material of the collar and is at least one selectedfrom the group consisting of PFA (perfluoroalkoxy), PTFE(polytetrafluoroethylene), ECTFE (ethylene chlorotrifluoroethylene), FEP(fluorinated ethylene propylene) and ETFE (ethylenetetrafluoroethylene), the bag being sized and shaped to pass through theopening in the housing and to expand such that the abrasion resistantreinforcing material can be in contact with at least a substantialportion of the inner surface of the housing; and a sealing member sizedand shaped to attach the collar to the opening in the housing andsealingly close the flexible bag such that the collar is not movable andthe contents of the liner are held in the container.